Compound cylinder



May 18, 1937- A. A. LOWEKE COMPOUND CYLINDER Filed May 27, 1935 2Sheets-Sheet 1 INVENTOR.

E R K O mm 0 YW AWM M MY. AB

May 18, 1937. A. A. QWEKE 2,081,056

COMPUND CYLINDER Filed May 27, 1955 2 Sheets-Sheet 2 :ii e w ENINVENTOR. A/o/Y' /4 0n/5K5 BYW l l m4 ATTORNEY.

Patented Msy 1s,l I192.1

NT OFFICE ooMPoUNn CYLINDER.

Aaron A. Loweke, Detroit, Mich., assignor to Hydraulio Brake Companporation of California y, Detroit, Miolufa vcoi-- Application May 27,1933, Serial No. 673,288

10 Claims.

This invention relates topressure devices. Broadly .the inventioncomprehends a compound cylinder and a piston therefor havingl two headsoperable in sequence to build up pressure, and means between the pistonheads automatically operable to transfer the load without loss from onepiston head to the other piston head after a predetermined pressure hasbeen obtained.

In the illustrated embodiment of the invention, a reservoir has formedin the bottom thereof a double diametral cylinder with that portion ofthecylinder having the larger diameter extending from the reservoir andprovided with a removable head. A compound piston is movable in thecylinder and may be readily extracted through the extended portion ofthe cylinder.

The piston has a plurality of heads of different diameters iitted intoportions of the cylinder having corresponding diameters. Arrangedbetween the piston heads are valves and control means therefor includinga spring-pressed piston operable upon predetermined pressure to renderthe piston heads ineffective.

A control means is operable rst upon a predetermined preure to releasea. valve in the piston head Vhaving the larger diameter to render thishead in'eiective, and, secondly, upon a higher predetermined pressure torelease a valve controlling a passage through the piston head having thesmaller diameter to return the uid to the reservoir.

An object oi' the invention is to provide a uid pressure device whichmay be used for various purposes, and particularly where it is desiredto build up high pressures.

Another object of the invention is to provide a iluid pressure deviceincluding a compound cylinder constructed to attain high pressureWithout an increase in the applied force.

A feature of the invention is a Acompound piston and means arrangedtherein operable upon predetermined pressures for rendering the pistonineffective. y

With these and other objects inview which may be incident to theimprovements, the invention consists in the parts and combination to behereinafter set forth and claimed, with the understanding that theseveral necessary elements comprising the invention may be varied incon-` struction, proportion and arrangement, without departing fromthespirit and scope of the appended claims.

In order to make the invention more clearly understood, I have shown inthe accompanying drawings means for carrying the same into prac- (Cl.Gil-54.6)

tical eifect without limiting the invention in'its useful applicationsto the particular constructions which, for the purpose of explanation,have been made a subject of illustration.

In the drawings forming a part of this specilicatlonzy Figure 1 is asectional view of a compound cylinder embodying the invention. n

' Figure 2 is a sectional view substantially on line 2-2, Figure 1,

Figure 3 is a top plan view,

Figure 4 is a diagrammatical illustration of a uid pressure( operatedsystem embodying the invention, y'

Figure 5 is a detail view of the piston illustrating the fluid pressureactuating valve mechanism in one position, and

Figure 6 is a detail view illustrating the valve mechanism in anotherposition.

Referring to the drawings for more speciiic details of the invention, I0represents a support having bolted or otherwise secured thereto ahousing l2 including a reservoir I4 having a fllling opening I6 ilttedwith a plug I8. The housing has an extended top portion 20 provided withan opening having a cover 22.

Formed integral with the housing and communicating with the reservoirl I4 is a sleeve. having itted therein a valve cage 26 containing aspring-pressed ball Avalve 28 controlling the passage or communicationbetween vthe sleeve and the reservoir. As shown, the passage has thereina pin 30 `fitted with suillcient clearance to permit free passage offluid or liquid. 'I'he pin extends into the reservoir and is adapted toopen the valve, movement of the pin in opening the valve being limitedby a stop 32 for arresting the actuator, to be hereinafter described.The sleeve also has threaded therein a coupling 34 for connecting areturn pipe 36.

'Ihe housing I2 has formed yintegral therewith in the bottom of thereservoir a cylinder 38 having a portion extending from the wall of thehousing. The cylinder has a' double diametral bore. The inner end ofthis cylinder is slotted as indicated at 40, and threaded in the outerend of the cylinder is a plug 42. As shown, the plug is axially boredfor the reception of a springpressed valve 44 and a coupling 46 for theattachment of a pipe line-48.

Positioned for reciprocation in the cylinder is a compound pistonincluding a small piston tted with small clearance in that portion ofthe cylinder having the smaller diameter. 'Ihis piston has acircumferential groove 52 communieating with the reservoir, a radialbore 84 communicating with the groove, and an axial bore 88communicating with the radial bore and with the sleeve. .The forcesupplying end of this piston has suitably secured therein acase-hardened insert 88 providing a suitable bearing surface for theactuator. The head of the piston has threaded axially. therein a doublediametral sleeve 60 and positioned on the head of the piston is acollapsible leak-proof cup 82 held in position by a spring 84 interposedbetween the cup and that portion of the sleeve having the largerdiameter.

The sleeve has a plurality of ports 88 providing communications betweenthe sleeve and the cylinder and a piston head 88 on the sleeve ispositioned for reciprocation in that portion of the cylinder having thelarger diameter. This head is fitted in the cylinder with smallclearance, or it may have channels 10 providing passageways for fluid orliquid. 'Ihe head has an axial oriilce 12 controlled as by a ball valve14 and a collapsible leak-proof cup 16 and a disc 18 on the head areheld against displacement by a spring 80 interposed between the disc 18and the plug 42 in the outer end of the cylinder.

Positioned for reciprocation in the sleeve 80 is a piston 82 havingl askirt 84 and a concentric portion 86 of smaller diameter than the pistonand .extending beyond the head of the piston. This extended portioncontrols the ball valve 14. As shown, the extended portion 86 has anaxial bore 88 and a plurality of ports 80 providing a passage throughthe piston controlled by a ball valve 92 urged to close the bore 88 by aspring 94 which also urges the piston 82 to actuate the ball valve 14 toclose the port 12. The head of the piston 82 has thereon a leak-proofcup 88 sleeved on the extended portion 86.

The extended top portion 20 of the housing has oppositely disposedbosses 88 and |00 bored for the reception of an operating shaft |02. Theshaft has a double diameter and that portion of the shaft having thesmaller diameter is threaded for the reception of a lever or actuator|04 arranged to actuate the piston and the valve 28. When in normalposition the actuator retains the valve 28 in open position so thatexcess fluid may be returned to-the reservoir. The shaft has acircumferential groove |08 in which is positioned a leak-proof washer|08 seated on an annular shoulder ||0 in the boss 88. The shaft also hasa knurled portion I2 to which may be secured an operating lever H4.

Assuming that the device is properly connected in a system and that thereservoir |4 and the cylinder 38 are lled with suitable liquid or fluid,by applying force to the operating shaft, the actuator |04 is moved fromthe stop 32 resulting in releasing the valve 28 whereupon the valvemoves to closed position. This movement of the actuator applies force tothe piston. During the initial movement of the piston, pressm'e isreceived on the piston head 88 movable in that portion of the cylinderhaving the larger diameter and iluid is drawn past the piston 50 and thecollapsible leak-proof -cup 82 into the cylinder forward of the piston50, and upon attaining a predetermined pressure by this movement of thepiston the ball 14 is urged by pressure from its seat to open the port12. This relieves pressure on the cup 16 and equalizes the pressure onboth sides of the piston head 68.

The pressure is then received by the cup 82 on the piston 50, also bythe cup 98 on the piston 82 and by the ball valve 82. This transfer ofthe pressure is eected without losses. Upon further movement of thepiston and attaining a second predetermined pressure, the ball valve 82is opened by the pressure to permit the uld to flow through the ports80, the passages 88 and 88, the axial bore 84, the groove 82, and pastthe body of the piston 50 to the reservoir.

As the piston moves to its retracted position, the valve 44 closes andretains the fluid in the system under pressure. This pressure isreleased when the actuator is moved to trip the valve 28 so that excessfluid in the system may be returned to the reservoir. As the pistonmoves to its retracted position, the cups 62 and 18 collapse and fluidis drawn from the reservoir past the cups into the cylinder, thusillling the cylinder for subsequent discharge stroke.

A uid pressure system including the compression cylinder is illustratedin Figure 4. In this installation the pipe line or conduit 48 controlledby the valve 44 has connected therein a plurality of motor cylinders||8. Each of the motor cylinders has a reciprocating piston ||8connected by a rod |20 to any suitable type of mechanismit may bedesired to actuate. In this particular installation the bleed conduit 38controlled by the valve 28 leads back from one of the motor cylinders H6to the reservoir |4.

In normal operation the valve 28 is closed so 1'7 that fluid surges backand forth through the pipe line V48 between the compression cylinder andthe motor cylinders. When the actuator is moved to its retractedposition the valve 44 is closed, and the valve 28 is tripped so thatexcess fluid in -the system may be returned to the reservoir.

Although this invention has been described in connection with `certainspecic embodiments, the principles involved are susceptible of numerousother applications that may readily occur to persons skilled in the art.The invention is, therefore, to be limited only as indicated by thescope of the appended claims.

Having thus described the various features of the invention, what Iclaim as new and desire to secure by Letters Patent is:-

1. A fluid pressure device comprising means for producing pressureincluding spaced piston heads each having an orifice, a sleeveconnecting the piston heads, and means in the sleeve for controlling theorifices operable at a predeterminedA pressure to open the orifices inone of the heads and at a greater pressure to open the orifices in theother head.

2. A fluid pressure device comprising means for producing pressureincluding spaced piston heads each having an orifice, a sleeveconnecting the heads, a valve controlling the orifice in one of theheads, a piston movable in the sleeve controlling the valve, said pistonhaving a passage, a valve controlling the passage, and means in thesleeve urging the valves to close the orifice and the passage.

3. A fluid pressure device comprising a double diametral cylinder, apiston movable therein having spaced heads each provided with an orice,one movable in that portion of the cylinder having the smaller diameterand the other movable in that portion of the cylinder having the largerdiameter, a sleeve connecting 'the head and communicating with theoriices and pressure actuated means in the sleeve for controlling theorifices operable at a prede- 75 termined pressure to open one of theorices and at a greater pressure to open the other orice.

4. A fluid pressure device comprising a piston having an orifice, asleeve on the piston communicating with the orice, a. piston head on thesleeve having an orice communicating with the sleeve, valvesin thesleeve for controlling the orlces, and means urging the valves to closedposition and yieldable at a predetermined pressure to permit the valvesto open successively.

5. A fluid pressure device comprising a piston having an axial orice, adouble diametral sleeve supported concentrically on the head of thepiston, a head on the sleeve having an oriflce, a valve controlling theorifice in the second-mentioned head, a piston movable in the sleevehaving a passage, a valve controlling the passage, and a tension memberin the sleeve urging the valves to close the orifice and the passage.

6. A fluid pressure device comprising a piston having an orice, a doublediametral sleeve in the head of the piston communicating with the orice,a. cup on the head of the piston, a head secured to the sleeve having anorice communieating with the sleeve, a cup on the head secured to thesleeve, a valve controlling the orice in the head secured to the sleeve,an orlced piston movable in the sleeve engaging the valve, a valve inthe piston in the sleeve controlling the orice in the piston, and atension member urging both valves to closed position andv yieldable atpredetermined pressures to permit the valves to open successively.

7. A uid pressure device comprising a reservoir having a doublediametral cylinder formed integral therewith, that portion of thecylinder having the smaller diameter extending into the reservoir andthat portion having the larger diameter extending from the wall oi' thereservoir, a piston movable in the cylinder having heads correspondingrespectively to the different diameters of the cylinder, the pistonbeing removable through that portion of the cylinder having the largerdiameter.

8. A pressure device comprising a piston, a double diametral sleevethreaded in the head thereof, a cup on the head of the piston, and aspring between the cup and that portion of the sleeve having the largerdiameter.

9. A pressure device comprising adouble diametral cylinder, a head onone end thereof, a piston movable in the cylinder, a double diametralsleeve on the head of the piston, a cup on the head of the piston, aspring between the cup and that portion of the sleeve having the largerdiameter, a head secured to the sleeve, a cup on the head secured to thesleeve, and a spring between the head on the sleeve and the head of thepiston.

10. A pressure device comprising spaced piston heads each having anorifice, a sleeve arranged concentrically to and connecting the heads, apiston movable in the sleeve having an opening in its head, a valvecontrolling one of the orices, a valve controlling the opening, andmeans urging the valves toward their seats.

AARON A. LOWEKE.

